Cellular wireless communications systems, for example, are designed to serve multiple wireless-enabled devices distributed over a large geographic area by dividing the area into regions called “cells”. At or near the center of each cell, a network-side access device is located to serve client devices located in the cell and commonly referred to as “access terminals” or “mobile stations,” terms which may be used interchangeably. Examples of mobile stations include cellular telephones, laptops, PDAs, and other wireless-enabled devices. A mobile station generally establishes a call, also referred to as a “communication session,” with an access point to communicate with other entities (e.g., servers) in the network.
The 1xEV-DO protocol has been standardized by the Telecommunication Industry Association (TIA) as TIA/EIA/IS-856, “CDMA2000 High Rate Packet Data Air Interface Specification,” 3GPP2 C.S0024-0, Version 4.0, Oct. 25, 2002, which is incorporated herein by reference. Revision A to this specification has been published as TIA/EIA/IS-856A, “CDMA2000 High Rate Packet Data Air Interface Specification,” 3GPP2 C.S0024-A, Version 2.0, July 2005. Revision A is also incorporated herein by reference. Revision B to this specification has been published as TIA/EIA/IS-856-B, 3GPP2 C.S0024-B, version 1.0, May 2006, and is also incorporated herein by reference. Other wireless communication protocols may also be used.